On a circuit board of an electronic device, such as a video recorder and a personal computer, a heat generator, such as an LSI, is mounted. In order to cool such heat generator, a cooling system using a heat pipe and a heat sink, for example, are used.
In a heat sink disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2009-150561, one-end portions of first heat pipes or one-end portions of second heat pipes are thermally connected to a plurality of heat generators. The other end portions of the heat pipes are thermally connected to the heat sink. A contact area of the first heat pipe with respect to the heat sink is different from that of the second heat pipe, thus the plurality of heat generators are efficiently cooled.
As a member for thermally connecting the heat pipe to the heat generator, a heat receiving block may be used. A heat receiving block has a heat receiving surface which contacts the heat generator and a fitting portion such as a hole in which an end of the heat pipe fits. The heat receiving block is thermally connected to the heat generator and the heat pipe.
By using a heat receiving block, it is possible to more efficiently cool the heat generator than when the heat pipe is thermally connected to the heat generator directly. However, a heat receiving block is a relatively large component among the components that are mounted on a circuit board. Therefore, the heat receiving block may restrict arrangement of the other components.